Performance improving on optical TDMA networks

In order to urge an optical TDMA network to be adopted as a practical private network, this paper explores how to apply the unused bandwidth to enhance the performance of a middle-load network. The medium access control protocol (the MAC) of the network uses the tight and loose approaches to control traffic. The accessible bandwidth of a node with the loose traffic-control approach (the LTC) can be larger than the traffic generated by the node. The difference between the accessible bandwidth and nodal traffic is called the added bandwidth of nodes. For a node with the tight traffic-control approach (the TTC), the accessible bandwidth of the node is just equal to the traffic the node generates. In the paper, the average waiting time of TDMA nodes (the waiting mean) is analyzed to obtain the upper and lower bounds of the LTC waiting means. The upper bound is the theoretical waiting mean resulting from the TTC. The lower bound is the theoretical waiting mean of the LTC. Both bounds and the simulative LTC waiting means will be contrasted to explore the effect of added bandwidth on network performance. After simulations, two effects are manifested. One is that the efficacy of improving performance is relative to the transmitted traffic of nodes. The smaller the transmitted traffic, the larger the efficacy of improving performance. The other is that the performance improved by added bandwidth can not be enhanced without restraint even if the added bandwidth is infinite.